


A Dangerous Rivalry

by jardinsdeminuit



Category: Diabolik Lovers
Genre: Blood Drinking, Dead Dove: Do Not Eat, Dubious Consent, Established Relationship, F/M, Laito is Laito, Lemon, Light Sadism, Oral Sex, Romance, Rough Sex, Smut, Threesome - F/M/M, that should be warning enough
Language: English
Status: Completed
Published: 2021-02-22
Updated: 2021-02-22
Packaged: 2021-03-12 16:34:08
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,517
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29637477
Author URL: https://archiveofourown.org/users/jardinsdeminuit/pseuds/jardinsdeminuit
Summary: A nighttime gardening session turns sour when Yui makes one too many mistakes and Yuma decides to punish her. Little do they know a third figure is watching them, and he has plans to make Yui's night a whole lot worse.
Relationships: Komori Yui/Mukami Yuuma, Komori Yui/Mukami Yuuma/Sakamaki Laito, Komori Yui/Sakamaki Laito, Mukami Yuuma/Reader, Sakamaki Laito/Reader
Comments: 10
Kudos: 19





	A Dangerous Rivalry

**Author's Note:**

> This was a request on Tumblr that I decided to turn into a full-length fic, since it features two of my favourite trash sons from the series. It was really fun stirring up tension between Laito and Yuma, and of course, poor Yui is (quite literally) stuck in the middle of it all.
> 
> Comments are love! ❤

“You're doing it wrong. _Again._ ”

I lowered my shears as Yuma stormed over. He pushed me back by the shoulder and lifted one of the sweet pea stems I'd been pruning between his thumb and finger.

“Are you stupid?” I've already showed you how to do these.” With a sigh, he took another stem and pointed to the wilted flower at the end of it. “ _This_ is a dead head. _This_ is what I need you to get rid of, not havking away at the vines or live flowers.” To demonstrate, he pinched the head off with his nails and let it drop to the floor. “Got it?”

I nodded, colour rising to my cheeks at having been scolded yet again. Not that this was anything unusual with Yuma. It seemed like every time I helped him out with his garden, I ended up making some kind of mistake, whether by trimming stems back too far or overwatering the plants. Even when I thought I was getting the hang of it, I could always rely on Yuma to pick out fault in what I was doing. He didn't mean it nastily: keen senses and decades of practice had resulted in him taking a great deal of pride in his pasttime, whereas I hadn't even planted a single flower before setting foot in the Mukami household.

We stood in the huge greenhouse at the end of the garden right now, in front of a wall of sweetpeas Yuma had been growing since the beginning of spring. Unlike the vegetables he usually grew, these were purely decorative. The thin vines twisted up the bamboo sticks he'd roped in place and exploded into little pink and purple flowers. The plan was that I started pruning away the dead heads at one end, Yuma at the other, and we met in the middle, though of course, he moved twice as fast as me. That it was hard to see by the light of the lamp on the floor between us didn't help my speed, either. Nor did the fact I could feel his eyes on me as I worked.

Only a few minutes had passed since my scolding when I heard Yuma's snort of annoyance again. “For fuck's sake, Sow.” He appeared beside me and grabbed a handful of vines. “You're cutting them too short.”

This time, I couldn't help but blurt out, “No, I'm not. I've done every one just like you told me to.”

Yuma bent down and picked up a withered flower. His hazel eyes burned as he shoved it in my face. “Look at the stem on that. You're butchering them.”

I peered at it. There was perhaps half an inch of stem attached to the flower, if that. Certainly not enough to warrant the level of anger he was showing me, though I'd sooner shear off the ends of my fingers than argue when he was in a mood like this. I'd made that mistake far too many times before.

Turning my eyes down, I muttered, “I'm sorry. It won't happen again.”

I kept on staring at his feet, the blood pounding in my temples as I awaited his response. To my surprise, he clicked his tongue and said, in a tone heavy with sarcasm, “'Won't happen again,' she says. If I didn't know better, I'd say there were other thoughts on your mind.”

I looked up to see him smiling, which only confused me further. I'd expected him to push me around, or at least shout at me some more. This sudden switch from anger to cheerfulness couldn't mean anything good.

“Yuma?” I said, a little uncertainly.

The vampire grunted, as if he were considering something. Then he threw his shears into a nearby plant pot and clapped his hands together, making me jump. “Right, I've decided. Time for a break.”

Before I could ask him what he was talking about, he bent over, grabbed my waist and slung me over his shoulder as easily as if I were a bag of compost. I yelped as my chest slammed into his back, suppressing the urge to kick at him for fear it would only worsen whatever strange mood he was in.

Yuma carried me past rows of plants and pots to the other side of the greenhouse, where a series of metal tables carrying seed trays stood against the glass. He selected one of the emptier ones, cleared a space with his free hand and dropped me on top of it. The sharp edge dug into my bare thighs painfully.

“I could have walked, you know,” I snapped.

Yuma laughed. “Where's the fun in that?”

He leaned forward and caught my lips with his own, swallowing any further protests. The action wasn't completely surprising – I'd suspected that any kind of 'break' Yuma proposed would involve something like this – but I froze all the same. Strong hands gripped my waist, pulling me to the edge of the table so that he could better lean in and claim my mouth.

“Hm? What's wrong, Sow?” he mumbled, noticing I wasn't returning his kiss with my usual enthusiasm.

I stared into his eyes. He was close enough for me to smell the sweat that clung to his body mixed with the rich, earthy scent of soil. The resulting combination was something utterly unique to him.

I could have lied, but he'd have seen through that in seconds. I shifted on the table. “You're not... angry about the flowers?”

Yuma raised an eyebrow. Then he grinned widely. “'Course I am. That's why you're going to repay me now.”

When he leaned in this time, I accepted his lips more readily. My heart fluttered in my chest, and I became aware of my own quickening pulse and the heat that spread from my head to my stomach and the tips of my toes. A soft groan rose from Yuma's chest as he moved his lips over mine, one hand leaving my waist to tilt my head backwards.

My mind was spinning by the time Yuma broke the kiss with a soft, wet _smack_. Instead of pulling away completely, he dragged his lips across my jaw, breath hot against my skin. Even with me sat on the table, he had to bend over a little to reach my neck.

“Don't think I can't feel your heartbeat creeping up,” he whispered into my throat. “You're getting off on this just as much as me, aren't you?”

“Of course no—” I started, only to be cut off by the feeling of something razor sharp tracing a line up the side of my throat. Yuma's fangs.

The laugh he gave this time was shorter and somehow heavier. “I don't even have to bite down to get you flustered. Is the feeling of my fangs on your skin really that exhilarating?”

I wanted to tell him no, but just like before, I knew he'd be able to see through my lies in an instant, especially with our bodies pressed this close. Plus, there was no ignoring the knot that gradually tightened at the base of my abdomen and made me squirm against him. Yuma must have sensed it too, as he pressed a kiss to the side of my neck and whispered, “Allow me to relieve you.”

He breathed in sharply before sinking his fangs into my throat. He'd bitten me in this exact spot countless times before, but that didn't stop me from gasping at the pain that shot through me. My hands flew up to grab at his shirt. I could hear my pulse throbbing in my temples, the sound of Yuma gulping down my blood like a starved animal.

His fingers were at his belt long before he broke away from my neck. My heart leapt as I looked down to see him undoing his zipper. His fingers moved nimbly, almost desperately.

“Your brothers. They'll see us through the glass,” I said, looking up the garden. I'd spent enough time in the Mukami mansion to know that the greenhouse was more than visible through the windows, even in the dark.

“So?” teased Yuma. “Afraid of showing everyone who you belong to?”

 _Not like this,_ I was about to say, when Yuma caught my lips in a short kiss, silencing me. My resolve melted away. There was no arguing with him like this, not when I could sense so much energy rushing through his veins.

He slipped a hand beneath my skirts and hooked his thumb around my underwear, pulling it aside enough for him to line his cock up with my opening. Then, slowly, he pushed forward.

As usual, the first few seconds were the worst. I buried my head in his shirt and grit my teeth to keep from crying out as he slipped inside me, stretching me apart. The angle I was sitting at hardly helped, either. I spread my legs and pushed my hips forward to try and make it easier for the both of us, though Yuma took that as an invitation to grab me by the hips and force more of himself in.

“Yuma... that hurts...” I moaned into his shoulder.

“Of course it does,” he said, his breaths already a little ragged. “This is your punishment for fucking up, after all.”

In one fluid movement, he slipped his hands beneath my thighs, lifted me up an inch or so and slid the rest of his length inside. I gasped, unable to muffle the sound completely with his shirt.

He began to thrust into me with long, hard strokes. The table shook beneath us, metal scraping against stone in time with his movements. I locked my legs around his waist and dug the heels of my shoes into his back. The force of his thrusts sent waves through me, until I could think of nothing else.

In my peripheral vision, something shifted. I ignored it at first, but then it happened again. I looked over Yuma's shoulder to see a dark figure standing in the greenhouse doorway.

“Yuma,” I hissed.

“What?” he grunted, not slowing his pace.

I hammered a fist against his back. “There's someone in the doorway.”

With a frustrated snarl, he turned to look over his shoulder. Then he jumped. “Aw, shit.”

He pulled out of me sharply and fumbled to pull his trousers back up. I lowered my head, my cheeks flushed hotter than I'd thought possible. I was glad had Yuma's wide shoulders to shield me from whoever was looking on.

He wrapped a protective arm around me and called out, “Oi, what d'you think you're doing here? This is my greenhouse.”

The sound of footsteps as the intruder walked between the plants was the only reply he received. I imagined it was one of the other Mukamis – Kou seemed the only one with the audacity to walk in on a situation like this – until I heard a short, high giggle. My whole body froze.

“It's a nice place. I like it.” The voice was silvery and all too familiar. I peeked around the side of Yuma's arm.

Laito stood behind a nearby row of tomato plants. His green eyes met mine and he smiled.

“Hi, Bitch-chan!” he said with a cheerful wave. “I can see you hiding there.”

“H-how long have you been watching?” I asked.

“A while.” Laito pulled a tomato off the vine, turned it over in his hand and dropped it to the floor. I could practically hear Yuma's teeth grind together. “Enough to know you're more than happy to mess around behind my back.”

Yuma repeated those last couple of words under his breath. Then he turned and marched towards Laito. His hand flew up to grab his collar. Laito could have moved out of the way in time, but instead he let himself be lifted up by his shirt until his tiptoes were barely touching the floor.

“ _Your_ back, huh?” Yuma growled. “What makes you think she belongs to you?”

At well over six feet, Yuma made even Laito look tiny as he loomed over him. Having been in Laito's position many times before, I knew firsthand just how terrifying Yuma could be when he got like this.

And yet Laito's smile didn't falter. If anything, it widened. “You're forgetting that Bitch-chan and I have a history. We did _so_ many wonderful things together back when she was living with us.” Laito touched a hand to his blushing cheeks and sighed. “I'm getting excited just remembering it.”

 _We only did them because you forced me to,_ I thought, but the words wouldn't come out. It wasn't that I was scared of Laito, but seeing him here so suddenly was enough to make me uneasy, especially if what he'd claimed about having been watching a while was true.

Yuma's grip around Laito's collar tightened. Then, clearly deciding he wasn't worth his time, he muttered, “Fucking pervert,” and shoved him back.

“Come on,” he snapped, storming over and grabbing me by the wrist. The table edge scraped across my thighs as he dragged me off it.

“Where are we going?” I winced. “You're hurting me.”

But Yuma didn't care. I had no choice but to let myself be pulled across the greenhouse. I assumed we were heading back to the mansion, where at least we'd be afforded the privacy of a locked room – assuming Laito didn't try to follow us, of course. It was hard to tell with him. Normal levels of decency weren't a concept that existed in his head.

Just before we reached the door, something grabbed hold of my other wrist. My heart fell. I turned to see Laito smiling at me with that unique combination of amusement and curiosity in his eyes that made me feel like he was peering into my thoughts.

“Hmm?” Yuma paused as he noticed I'd come to a stop.

“It seems like such a shame to end things here,” said Laito, “especially since I interrupted at such a... heated moment.”

He turned my hand around to reveal a smudge of blood clinging to my little finger. I must have brushed the bite wound on my neck at some point. Making sure his eyes never left mine, Laito slipped my finger between his lips and pulled it out slowly, sucking off the blood as he did so.

“What are you getting at?” Yuma snapped, though the slight waver in his tone suggested he knew as well as I did what Laito was talking about.

As if sensing my sudden comprehension, Laito placed his free hand on the side of my neck and traced his fingers downwards. His nails overhung his fingertips by the smallest length, unlike Yuma, who kept his as short and practical as possible. While they were both vampires on the surface, it was the little differences like this that set the two of them worlds apart.

Hence why it came as twice as much of a shock when Yuma shoved me forward. “Fine. Do what you want.”

Laito caught me in his arms. For a moment, I was too stunned to move. Then panic kicked in, and I tried to push off his chest.

The struggle didn't last long. Laito spun me around so that my back was against him, one arm wrapped across my chest in a vice grip, the other looped around my waist. He laughed and pressed a kiss to my bite wound. His cold lips sent trickles of ice down my back.

“You gave up so easily, Bitch-chan,” he purred into my neck. “Could it be you _like_ having two men fight over you like this?”

It wasn't that I'd given up so much as I knew which battles were worth fighting and which weren't. There was no way I could stand up to a vampire like Laito and win.

“Just let me go,” I mumbled.

“Is that what you really want?” Slowly, Laito slipped the hand holding my wrist downwards, tracing it across my thigh beneath my skirt until he reached my underwear, still wet from where Yuma had taken me. I trembled as he ran a finger along my opening through the material, gasping as he put pressure on my clit.

A sigh fell from Laito's lips. “Just as I thought. You're aching for this.”

He slid a finger beneath my underwear into my heat, the feeling of his cold skin making me buck my hips in protest. All the while, Yuma looked on with a stony expression, as if he were measuring my reactions to Laito's teasing.

I was torn. One the one hand, I felt like I could die from embarrassment on the spot. Yet there was a part of me that wondered just how far this situation could go. The gentle but insistent movement of Laito's fingers as he glided in and out of me, so different to Yuma's rough touch, made me want to melt in his arms.

But when had things ever been different? Laito had a knack for delving deep into my subconscious and bringing up every immoral desire that lurked there, turning my body traitor against me. I hated him for it. I hated Yuma for pushing me into this situation in the first place. Most of all, I hated myself for not being strong enough to refuse them.

Yuma snorted in defeat. “I knew it. You're no better than that filthy pervert behind you, are you, Sow?”

He swept forward, snatched me from Laito's arms and threw me down. My palms scraped against the stone floor as I landed. A pair of hands pulled me backwards by my hips, and then I felt a sharp pull and heard material being torn. The suddenly rush of cold air between my legs told me Yuma had just ripped my underwear away.

I'd barely managed to prop myself up on my arms when the hiss of a zipper met my ears. This time, Yuma thrust into me with vigorous abandon, forcing his whole length inside with a single snap of his hips. I cried out at the sudden rush of pain. He began to move straight away, not giving me time to adjust to his size, making me grit my teeth and writhe against him.

As if to make matter worse, I heard Laito giggle nearby. The next moment, he fell to his knees in front of me, took my chin in his hand and tilted my face up. Rays of moonlight glimmered in his red hair.

“Those are some beautiful noises you're making, Bitch-chan,” he sighed, “but I think we can find an even better use for that mouth, hm?”

I was too overwhelmed to respond. My eyes were blurry with tears, my hands curled into fists against the ground.

Laito grabbed me by the back of the hair and pulled me forward until my cheek rested against his zipper. I felt his cock straining on the other side. He couldn't have made it any more obvious what he expected me to do.

“Just remember who you belong to, Sow,” Yuma warned between grunts.

As if I could have forgotten with the way he was thrusting into me.

Unable to hold back anymore, Laito undid his trousers and pulled his underwear down to reveal his length. He placed his hand on my face, running his thumb along my cheekbone before he slipped it between my lips, forcing my mouth open. He smiled.

“Don't worry, Bitch-chan. I'm sure you'll have a good idea of who owns you once I'm finished,” he whispered, and lowered the tip of his cock to that it was lined up with my mouth.

Instead of pushing himself into me all at once, Laito allowed me to move onto him at my own pace – a hard task with Yuma's thrusts rocking my body so violently. I managed to catch his tip between my lips and slide the first inch in. My tongue flicked out to lap up the bead of precum. A short, high gasp escaped his mouth.

Yuma growled. “Ridiculous.”

A particularly hard slam of his hips that I imagined was purely punitive knocked me forward, forcing me to swallow more of Laito's cock. I had to resist the urge to gag as he hit the side of my throat.

“Careful, now,” Laito purred, placing a hand on the underside of my jaw and spreading his fingers across my throat. “You don't want to break her, do you?”

“Don't tell me what to do,” Yuma snarled.

Sandwiched between the two of them, I felt shame and excitement mingle in a way I'd never experienced before. This was so utterly _wrong_ , and yet I was overcome by a thrill that tightened my core and made me tremble with every possessive thrust. It seemed that just a while ago, I'd been worried about the other Mukamis spying on Yuma and I from the mansion, when in the end, we'd attracted a different kind of visitor altogether.

Laito's hand tightened around my throat as I pulled back my head and slid onto him again. I wondered if he could feel his cock gliding in and out of my mouth through the skin. I traced my tongue along his length and flicked it against his slit, coaxing soft, breathy moans from his lips.

Yuma's fingertips dug into my hips. His thrusts were speeding up now, my bare thighs slapping against his. I lifted a hand and wrapped my fingers in Laito's trousers. It was all I could do to keep my balance as Yuma mercilessly bounced me against him. I'd slept with him enough times to know from his breathing alone that he was close to finishing, and all the better for it. My body felt like it was ready to split in two.

Seeing that my attention was being drawn away from him, Laito moved his hand from my throat to the back of my head, gathered up a bunch of hair and squeezed. The sudden jerk of pain snapped my thoughts back to him.

“Eyes on _me_ , Bitch-chan,” he whispered, a hint of danger in his tone.

He began to meet the movement of my head with small thrusts of his hips. I wanted to scream with the intensity of it all, but all I managed with his length in my mouth was a muffled whimper. My body didn't belong to me anymore. I could move for fear of losing my balance, couldn't fight back, couldn't _breathe_. All I knew was the thrill of being used, inside and out, and the hot, simmering pleasure it stirred in me.

A heavy groan met my ears, and I realised Yuma had finally reached his climax. He arched his back against me, nails digging into my hipbones so hard it felt like he was breaking the skin. I squeezed my eyes shut as a new round of tears stung them.

Yuma pulled out of me sharply. My inner thighs were soaked, though at this point, I wasn't sure whether it was my fluids or his that dripped down them. Laito breathed in deeply. No doubt he could smell the scent of my arousal as keenly as I could taste him on my tongue.

Now that I was free from Yuma's grip, Laito pulled my head back off him, giving me a precious moment to breathe. My face felt a mess. Spittle wet my lips, a little of it running down my chin. My jaw ached from having taken him so vigorously for so long.

“Oh, we're not done yet. I told you I'd make you mind, didn't I?” Laito purred, and again, I detected that undertone of danger that made me shiver.

He sank to the ground so that he was kneeling. His cock was hard enough that it almost touched his shirt and glistened from where it had been in my mouth.

I lowered my head and caught him between my lips. This time, I moved with long, deliberate strokes, pulling back until only the tip remained in my mouth before sliding down again in a rhythm that had him moaning my name over and over. I placed my hands on his thighs and spread my fingers wide. He quivered beneath me.

The feeling of something brushing against my heat made me jump. For a terrifying moment, I thought Yuma was preparing to enter me again, but then I felt the tickle of hair against my leg and something wet curl against my opening. I stuck my arse in the air, urging him to push his tongue deeper, groaning when he reached my clit. The angle of my body made it a little difficult, but eventually he managed to latch on, lapping up my wetness and swirling the tip of his tongue over my sensitive spot.

Laito's fingers tightening in my hair was the only warning I got before he spilled his seed into my mouth. The next thing I knew, my own climax tore through me. I lifted my head and gasped as waves of heat pulsed from my core, setting my nerves alight, making me buck and tremble against Yuma's mouth.

When I finally came down from my high, it was as if all energy had drained from my body. I wanted to collapse to the floor then and there. Laito's breaths came fast and heavy in the wake of his release. He ran a hand through my hair to smooth out the locks he'd ruffled and laughed.

“How utterly _shameful_.” He drew out the last word so that it sounded like he was singing it. His thumb traced along my bottom lip, brushing away the wetness he'd left behind. Then he pulled his trousers up and stood.

It seemed strange that after everything that had just happened, Laito would just up and leave. But, I realised, he'd already gotten everything he wanted: his own pleasure and my humiliation at the hands of two vampires. I watched him walk to the door, place a hand against the frame and turn.

“The three of us should hang out together again. This was fun,” he said as cheerfully as if he were talking about a coffee shop date. Then he stepped out into the night and was gone.

Yuma clicked his tongue. “Aristocrat bastard.”

I sank to the ground. My body ached from head to toe. I wasn't sure which was worse: the embarrassment of what I'd just done, or the fact I'd actually _enjoyed_ it. Laito was right. I really was shameful.

“What d'you think you're doing?” Yuma snapped behind me.

I was about to turn when he seized me by the shoulders and held me against the ground. I didn't have the energy to fight him. Not anymore.

“You really messed up letting there, letting that arsehole brag about claiming you and all that.” He pushed his mouth up to my ear and chuckled. The sound made my heart sink with dread. “This is far from over. Now it's just the two of us. You've got a lot of making up to do, Sow.”


End file.
